A device of this type comprises a tappet and a roller mounted rotatably on the tappet and provided to cooperate with a cam synchronized with the camshaft of the internal combustion engine in such a way that rotation of the camshaft results in the periodic displacement of a piston of the pump bearing against said tappet to enable distribution of fuel.
The tappet of such devices is usually implemented as a single relatively solid piece produced, for example, by cold forging. The roller of the device is generally mounted rotatably on the tappet via a separate spindle. This spindle is conventionally mounted on the tappet by upsetting or crimping in lateral bores in the walls of a sleeve which partially accommodates the roller.
In order to avoid a phenomenon of major friction between the ends of the spindle protruding from the bores and the inner walls of the guide bore formed in the associated housing which guides an axial movement of the tappet, it is known to fix the spindle in the bores so as to avoid movement in the axial direction. A circlip or plug, for example, may be used for this purpose. This fixing necessitates an additional assembly step and an additional element.
Another solution consists in forming the ends with convex surfaces. This makes the spindle, and consequently the whole device, rather expensive.
Furthermore, the document FR 2946406 proposes providing a support body for the roller fixed in a sleeve of the tappet. The ends of the spindle are fixed, for example by a press fit, in through-holes formed in a peripheral wall of the support body and disposed opposite one another.
This fixing makes the assembly rather complex.
The support body is mounted in the sleeve by a press fit, welding or brazing. Insufficient strength risks allowing undesirable displacement of the support body in the sleeve, and excessive force or heat risks causing deformation of the sleeve while the body is being installed, such as to impede sliding of the sleeve in its bore.
It is the object of the present invention to eliminate these disadvantages. More particularly, the present invention aims to provide a cam follower roller device which is less expensive while at the same time allowing correct sliding of the tappet in the bore guiding an axial movement of the tappet, and which is reliable, economical and easy to produce and assemble.